I am currently building a 880 block vortec heads, full roller setup. I am using my existing v-belt setup and am wanting to know if anyone has experience with a R4 (pancake compressor) and center bolt valve covers clearing on the driver side. I had to get fabricated aluminum valve covers because of the roller rockers. Any help would be appreciated.

A potential problem may be inadequate clearance between the top of the valve cover and the compressor hose manifold. There is a gap of only ~5/8" between the top of a factory stamped steel cover and the hose header with the compressor drive belt properly adjusted. You need to allow space for the compressor to rotate on its pivot for belt replacement and adjustment.

Do you actually need the added height of fabricated valve covers determined through clearance measurements? My 355 with AFR heads runs 0.560" valve lift through 1.6:1 aluminum rollers and "near factory height" aluminum valve covers and have adequate clearance between the valve train and covers verified through measurements and clay impressions. You should seriously consider a rev kit to control the added mass of the lifters and help contain them in the event of upper valve train trouble. Make sure the pushrods are suitable to the task.

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RichIt's difficult to know just how much you don't know, until you know it....In other words... if people learn by making mistakes, by now I should know just about everything!!87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)